Non-linear editing (NLE) systems are known for video (2D) and audio (sometimes referred to as “1D”) systems. NLE systems for video and/or audio include systems manufactured by AVID, Quantel and others. Non-linear video editing systems allow a user to join, arrange and/or modify digital or digitized source information to create a final cut, or edit, for rendering to appropriate storage media or output. The systems are non-linear in that the sources are not generally limited to being accessed in a linear manner, but instead permit random access. For example, the last three seconds of a ten second digital video source can be accessed without accessing the first seven seconds, or individual frames in the digital video can be accessed and/or combined as desired. Non-linear audio editing systems allow a user to easily and efficiently manipulate digital or digitized audio sources to produce a desired final output, often referred to as a final edit of “cut”.
In practice, an NLE system for video can, for example, be used to construct the video portion of a television advertisement for a new model of car, by connecting digitized source video of the new car driving on a country road, digital source video of a driver in the car and digitized source video of the car in a wind test tunnel with engineers standing about it. An NLE system for audio can be used to create an audio soundtrack for this advertisement, comprising a selection of classical music, in digital from, mixed with a narrator's voice-over, also in digital form, discussing the features of the car and various sound effects sources which are also mixed, at appropriate time points, with the music and narration sources. The video and audio final edits are than rendered to an appropriate sink, such as a VTR, RAID array, or a monitor, to obtain the finished commercial.
NLE editors represent the available sources (video or audio) as objects in a graphical user interface (GUI), the objects commonly being referred to as clips, which are positioned and/or manipulated with respect to a time line for the edit. Various effects, such as fades, dissolves, wipes, blends, etc. can be applied to the clips to obtain the final edit.
Known techniques for editing 3D animations have comprised the rendering of the 3D animation to 2D media (video) which is then edited in a conventional manner, such as with the above-described NLE. The 2D media rendered from the 3D animation is treated as any other 2D source material, such as digital video, and can be combined with such other source material, as desired by the director.
If the director requires a change to the 2D rendering of the 3D animation, for example to have a character walk past a fixed background at a faster rate, or to have the contents of the 3D animation composited together in a different order, the director must instruct an animation artist as to what is desired and the animation artist will then invoke the required animation tools to modify the animation and to re-render it to 2D media. This new 2D material would then be provided to the director to replace the previous material.
While these techniques have provided reasonable results in the past, it is desired to have a method and system of editing and/or modifying 3D animations which is easier to employ, more efficient than prior art editing techniques and which provides a flexible creative environment for directors, editors and artists.